Ever wonder why celebrities are all clustered together in the same neighborhoods? It's for several reasons, but mainly it's because those 'hoods are prime real estate -- and they were even before the celebs moved in.

The gated celebrity compound, built in 1948, is perfect for anyone looking for some privacy; the house is situated on almost two acres of land down a long private driveway, with nothing behind it but a beautiful view of the Los Angeles city skyline.

This week brought the news that legendary radio personality Casey Kasem and his wife Jean Kasem were putting their Holmby Hills mansion on the market for a cool $42 million. Sure, it's pricey, but here are 40 reasons to buy it...